The following summary describes five projects that attempt to investigate, at the molecular level, the roles of a number of molecules including, kinesin light chains, rab 3, p67 a novel activator of neuronal Cdk5, the modulatory neuropeptides buccalin and myomodulin and acidic calponin, play in neural function. Kinesin light chains, rab 3 and p67 are proteins that either directly or indirectly affect synaptic vesicle transport or fusion. We are currently attempting to address protein function by mutation and knock-out analysis by homologous recombination with kinesin light chains and p67 or by protein expression and microinjection in the case of rab3. We have previously characterized the peptide families of buccalin and myomodulin from the sea hare Aplysia californica and are currently examining how they collectively contribute to pre- or postsynaptic neuromodulation. The molecular characterization of receptors, the signal transduction cascades that are activated as a consequence of binding and the target proteins downstream of activation are also actively being pursued. Acidic calponin is a 36 kDa novel isoform of the actin binding protein calponin. Immunofluorescence studies using peptide specific antisera to its unique C-terminal tail domain have localized the protein to areas of high membrane turnover, particularly, the cleavage furrow of dividing cells, growth cones of neurons and sites of injury. Further research will be directed towards elucidating its role in wound healing and nerve regeneration.